Laminous multi-polymeric high amperage over-molded connector assembly for plug-in hybrid electric vehicle charging

ABSTRACT

In an electrical connector for an electric vehicle, the spring latch is not sealed; instead, the connector body has holes allowing water entering the spring latch mechanism to drain harmlessly out of the connector. A forward-facing LED or other light source acts as a flashlight. Once the connector is connected, the forward-facing LED is switched off, and a rear-facing LED or other light source is switched on to confirm that the connector is connected and capable of charging the vehicle. The connector is produced by overmolding in a three-layer configuration, where each layer is formed of a material having advantageous materials for that layer&#39;s position in the connector.

REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication No. 61/430,456, filed Jan. 6, 2011, and U.S. ProvisionalPatent Application No. 61/482,459, filed May 4, 2011. The presentapplication is also a continuation-in-part of U.S. Design patentapplication No. 29/382,230, filed Dec. 30, 2010, currently pending. Thedisclosures of the above-referenced applications are hereby incorporatedby reference in their entireties into the present application.

FIELD OF THE INVENTION

The present invention is directed to an electrical connector forsupplying power to an electric vehicle and more particularly to such aconnector having improved resistance to water in the environment andimproved user-friendliness.

DESCRIPTION OF RELATED ART

Electric vehicles are increasingly receiving attention. These includeplug-in hybrid vehicles such as the Chevrolet Volt and purely electricvehicles such as the Nissan Leaf.

Electrical connectors for recharging the batteries of electric vehiclesare standardized in North America by Society of Automotive Engineers(SAE) standard SAE J1772. Other applications, such as forklifts andindustrial equipment, may also adopt that standard.

According to that standard, the front of the connector has astandardized shape and five pins in a standardized layout, so that allconnectors work with all electric vehicles. The five pins are two ACpower pins, a ground pin, a proximity detection pin and a control pilotpin. Regarding the rest of the connector, the manufacturer of eachconnector has some discretion. Known connectors typically use springlatches to secure the connector to the vehicle during charging.

Since such connectors are typically used outdoors, environmentalconsiderations, such as water, must be taken into account. For example,water may get into the mechanism of the spring latch and cause corrosionor other degradation. The usual way to prevent such degradation is touse a rubber seal to protect the spring latch. However, seals fail.

There are also the problems of using the connector at night, when themotorist may not be able to see properly, and of letting the motoristknow when the connector has been fully and properly inserted.

Moreover, known connectors are typically manufactured from multipleparts. As a consequence, they can be expensive to manufacture and proneto failure.

To date, all solutions currently available in the Electric Vehicle (EV)market space are constructed from two halves (or clamshells) which aremechanically assembled with tamper-resistant fasteners such as Torx™screws. The old or current SAE J1772 mechanically assembled connectorscurrently allow water to enter the handle assembly, leading anopportunity for ice and debris to become trapped. Additionally, theclamshells add a bulky appearance at the handle and overall body, whichis driven by the additional mechanical features required to resistvehicle roll-over and crush requirements, as stated in UL 2251. Thesecurrent devices are suitable for garage and indoor applications. Whenused outdoors, these clam-shell designs may exhibit shorter life cyclesdue to exposure to the elements.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to address the aboveconcerns.

It is another object of the invention to provide a low-cost, attractive,ergonomic and adaptable solution.

To achieve the above and other objects, the present invention isdirected to a connector having at least one of the following features.

The spring latch is not sealed; instead, the connector body has holesallowing water entering the spring latch mechanism to drain harmlesslyout of the connector. A forward-facing LED or other light source acts asa flashlight. Once the connector is connected, the forward-facing LED isswitched off, and a rear-facing LED or other light source is switched onto confirm that the connector is connected and capable of charging thevehicle.

The connector is produced by overmolding. For example, the connector canbe produced in a three-layer configuration, with potting material, apremold, and a one-piece overmold. Each of the layers can be formed of adifferent material that gives it the properties needed for its locationin the connector. The modular design allows for faster product updatesand a common platform for product diversification.

The above features can be combined in any way.

The problem being solved by this invention is offering the EV (electricvehicle) market space (such as Original Equipment Manufacturers (OEM)and Electric Vehicle Supply Equipment (EVSE) manufacturers) a ruggedizedand integrated overmolded SAE J1772 connector and cable assemblysolution that offers reduced life-cycle costs and improved productreliability, and that also reduces the risks of tampering and vandalismassociated with mechanical locking features and hardware (such as Torx™Screws). This over-molded solution offers exceptional environmentalprotection from the extreme environmental elements which may include:water, ice, dust, ultra-violet rays, oils and automotive fluids.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment will be set forth in detail with reference to thedrawings, in which:

FIGS. 1-8 are various views of the connector according to the preferredembodiment and of various components thereof; and

FIGS. 9A-21 are views showing steps in the production of the connectorof FIGS. 1-8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment will be set forth in detail with reference to thedrawings, in which like reference numerals refer to like elementsthroughout.

As shown in FIGS. 1-8, the connector 100 according to the preferredembodiment includes a connector front piece 102 with a plurality of pins104, 106, 108, 110, 112. In the preferred embodiment, the connectorfront piece 102 and the pins 104-112 follow the standard SAE J1772. Thepins 104-112 are electrically connected to a cable 114 at a locationwhich is sealed inside of the connector front piece 102 with potting116. A connector body 118 is formed over the connector front piece 102and the cable 114 by a premold 120 and an overmold 122. The premold 120and the overmold 122 are formed with ridges 124, 126 to increase thestrength of the connector body 118. The connector body has a latch area128 with a spring latch 130 having a pin 132 and a spring 134.

A first LED or other light 136 can be provided to act as a flashlight,so that the user can use the connector at night in situations of poorlighting. A second LED or other light 138 can be provided on the back toindicate when the proper electrical connection between the connector andthe vehicle is achieved, at which time the first LED is switched off.Circuitry 140, such as a printed circuit (PC) board to be describedbelow, is provided for controlling the LED's.

The latch area 128 does not have to be sealed against water. Instead,water entering the latch area 128 exits through holes 142. As shown,there are three holes 142 on either side of the latch area 128,extending through the overmold 122 and into the latch area 128. Theholes 142 are open to the latch area 128 at a bottom surface 144 of thelatch area 128 so that there will be no places for the water toaccumulate. However, any suitable number and configuration of holes canbe used instead of, or in addition to, the holes shown.

For example, in use in a rainy situation, rain water incident on theconnector 100 enters the latch area 128 by flowing around the springlatch 130. Instead of accumulating in the latch area 128, the waterexits the latch area 128 through the holes 142. As noted above, theholes 142 are positioned relative to the bottom surface 144 of the latcharea 128 so that all of the water drains out of the latch area 128rather than forming puddles below the holes 142.

The holes 142 are shown as extending horizontally to facilitateovermolding. The left and right components of the mold used in theovermolding can have projections corresponding to the holes 142 and thusform the holes 142. After the overmolding process, the left and rightcomponents are pulled off in a horizontal direction to pull theprojections out of the holes 142 thus formed. However, the configurationof the holes 142 can be varied in accordance with various manufacturingtechniques. For example, in different manufacturing techniques, theholes 142 could slope downwardly from the latch area 128 or even extendvertically downwardly from the latch area 128. Moreover, holes 142 canbe formed in any other suitable manner, e.g., by drilling.

Still other configurations are possible. For example, the latch area 128could have a bottom surface 144 that is flat or that is crowned to urgewater out through the holes 142. Also, while the holes 142 are shown aselongated, they could have any suitable shape, e.g., round.

The preferred embodiment provides an overmolded, ruggedized, and robusthigh-amperage SAE J1772 connector assembly. The production of thepreferred embodiment begins with an insert molded SAE J1772 10 ampthrough 90 amp connector, shown in FIGS. 9A and 9B as 146, made of apolycarbonate material with a UL94 V-0 flame rating with anenvironmental (f1) ultra-violet rating and a relative thermal index(RTI) equal to or exceeding 100 for electrical and physical impact andstrength characteristics, as specified by the standard UL 2251.

The SAE J1772 connector body architecture 146 is that of a rigid bodydesign, which incorporates mechanical features promoting cross-linkingadhesion and/or enabling mechanical bonding and mechanical lockingfeatures with the premold 120 and the overmold 122. These mechanicalfeatures may include flow-through channels, pierced holes, raisedjoggles or ridgelines.

The connector body contains five 353½ hard brass contacts 104, 106, 108,110, 112, as described above, which can be silver or gold plated. Thetwo Size 8 power contacts 104, 112 incorporate elliptically wound highamperage and low insertion force internal helical springs 148 to enablehigher amperage with reduced opportunities for heating due tomicro-arcing, as well as offering additional opportunities of successfor reverse compatibility to vehicle inlets (IAW SAE J 1772)manufactured by other manufacturers. These internal helical springs 148also aid in accommodating the natural tendencies of process shift overtime. The springs 148 can be configured as a plurality of toroidalsprings, as shown, e.g., in U.S. Pat. No. 4,810,213 to Chabot, whosedisclosure is hereby incorporated by reference in its entirety into thepresent disclosure.

The insert molded SAE J1772 connector body 146 also incorporates a flameretardant (FR) UL listed closed cell gasket 150 on the mating face toaid in the prevention of attack on the contacts from corrosive gasessuch as carbon dioxide, sulfur dioxide, and hydrogen sulfide.

The connector body 146 is then assembled to an FFSO UL listed cable 114,shown by itself in FIG. 10, by means of a soldering operation toaccommodate the pin-out diagram as specified in SAE J1772, as shown inFIG. 11. The soldered contacts of the insert molded SAE J1772 allow forimproved cable retention of the overall assembly as well as reducedopportunities for micro-arcing and stray strands, which could lead torisks of shorts and ground faults, reducing the life cycle of theproduct. Additionally, soldered contacts provide for an additional levelof defense to deter the wicking and capillary effect of moistureabsorption at the exposed contacts. Water and moisture absorption, orwicking, accelerates copper corrosion and reduces the product lifecycle, which may result in higher amperage draw from the branch circuitresulting in excessive heat and customer dissatisfaction.

An environmentally sealed micro-switch sub assembly 152 is soldered toan FR-4 PC UL listed PC board 154, which incorporates one 150 Ohm ½ wattresistor 156 and one 300 Ohm ½ watt resistor 158, to implement thecircuitry 140 described above as a micro-switch assembly. A grommet,shown in FIGS. 13A and 13B as 164, is then added to the micro-switchsub-assembly 140 and assembled into position, as shown in FIG. 14. Thegrommet is manufactured from a polymeric molding compound which is UL94V-1 flame rating with an environmental (f1) ultra-violet rating and arelative thermal index (RTI) equal to or exceeding 90 for electrical andphysical impact and strength characteristics, as specified by UL 2251.The assembly 152 and board 154 are attached to the connector body 146,as shown in FIG. 15, by means of soldering the two flying leads(proximity and ground) 160, 162 to the proximity and ground pin contacts106, 108, enabling the DC pulse signals required by the SAE J1772Standard. This PC board 154 also provides for the silver path provisionsto incorporate LED signals for charge and flashlight requirements thatmay be activated or required by the EV SE.

When the soldering operation has been completed, the connector body 146,PC board assembly 154, and cable 114 are environmentally anddielectrically potted, as shown in FIGS. 16A and 16B, with a two-partpotting compound 166 that has a UL94 HB or V-0 flame rating and arelative thermal index (RTI) equal to or greater than 90 for electrical,physical impact and strength characteristics, as specified by UL 2251,to form the potting 116. This potting compound 166 will then be curedeither by overnight stall, or with a heat assist manufacturing aid. TheFFSO electric vehicle cable jacket, insulated conductors and solderedconnections will be encapsulated with this two part potting compound.

This potting compound 166 provides for the first level of defense todeter the wicking and capillary effect of moisture absorption at theexposed contacts. Copper stranding can, over time, enable a capillaryeffect in which moisture wicks from the exposed contact area into thecopper stranding which accelerates copper corrosion and reduces theproduct life cycle, which may result in higher amperage draw from thebranch circuit resulting in excessive heat and customer dissatisfaction.The potting compound 166 also offers dielectric properties, furtherinsulating the assembly from potential in air arcing between the powercontacts and ground. This potting compound 166 is the foundation inwhich the additional polymeric materials will use for additionalstructure and support within the design.

After the two-part environmentally and dielectrically potted compound166 has cured and outgassed completely to form the potting 116, apre-mold 120 will then be molded over the sub-assembly that includes theconnector body 146, the FFSO electric vehicle cable 114, and the pottedcontact, as shown in FIG. 17. The pre-mold is a high impact Polyamide(PA6 or PA66) based material with a UL94 V-0 flame rating and a relativethermal index (RTI) equal to or greater than 100. Other speciallyengineered compounds, such as glass filled polyethylene terephthalate(PET), acrylonitrile butadiene styrene (ABS), thermoplastic elastomer(TPE), thermoplastic vucanizate (TPV), or high impact polypropylene(HIPP), can be used. The pre-mold 120 encapsulates the subassembly,providing for the ‘backbone’ of the architecture, as well as addingadditional environmental and dielectric properties to the overall SAEJ1772 molded connector assembly system. The pre-mold 120 includes holes168 corresponding to the holes 142 of the finished product.

The pre-mold architecture is that of a rigid body design, whichincorporates mechanical features promoting either cross-linking adhesionand/or enabling mechanical bonding and mechanical locking features of anouter ‘over-mold skin’ layer. These mechanical features may includeflow-through channels, raised joggles or ridgelines, or depressedvalleys and flow-through T-channels.

The over-mold or skin, shown in FIG. 18 as 122, is for user interface,impact energy absorption, abrasion resistance, fluid and gasolineresistance and overall ultra-violet (UV) protection of the overall SAEJ1772 molded connector assembly system. The overmold material of the SAEJ1772 Connector Assembly has a UL94 HB or V-1 flame rating and arelative thermal index (RTI) equal to or greater than 90 for electrical,physical impact and strength characteristics, as specified by UL 2251.Alternate thermoset materials, such as EPT, EPDM, and silicone or liquidsilicone injection, may also be incorporated to accommodate the physicaland performance requirements of the outer skin.

Once the system is completely molded, a latch arm 130 manufactured froma polymeric material such as polycarbonate (PC) with a UL94 V-0 flamerating, an environmental (f1) ultra-violet rating and a relative thermalindex (RTI) equal to or exceeding 100 for electrical and physical impactand strength characteristics, as specified by UL 2251, is attached. Thislatch arm is attached by means of a molded or stainless steel (300Series) pin. The latch provides for the mechanical interlock to the SAEJ1772 vehicle inlet as well as the mechanical lever activating themicro-switch sub-assembly prior to commencing charging as well as uponcompletion of charging. The steps of attaching the latch arm includeinserting the latch spring 134 into the latch area 128, as shown in FIG.19; inserting the latch arm 130 over the spring 134 into the latch area128, as shown in FIG. 20; and inserting the latch pin 132, as shown inFIG. 21.

Additionally, the market currently only offers 30 AMP and 75 AMP listedassemblies, which are mostly governed by the cable and contact size. Thetechnologies implemented in the preferred embodiment allow a highercurrent rated (higher amperage) cable assembly to future proof thedesign for any DC fast charge requirements.

The preferred embodiment provides a ruggedized and robust SAE J1772overmolded connector assembly incorporating dielectric and environmentalpotting compounds, with an integrated polymeric substrate and overmoldedpolymeric skin offering protection from extreme and harsh environmentalconditions. The preferred embodiment combines an overmolded integratedpolymeric (laminated) approach and an integrated PC board withmicro-switch and provisions for LED lights for a charge indicator and aflashlight. The solution offers reduced life-cycle costs, improvedproduct reliability, and a reduced risk of tampering and vandalismassociated with mechanical locking features and hardware (such as Torx™screws). This over-molded solution offers exceptional environmentalprotection from the extreme environmental elements which may include:water, ice, dust, ultra-violet rays, oils and automotive fluids.

While a preferred embodiment has been set forth above, those skilled inthe art who have reviewed the present disclosure will readily appreciatethat other embodiments can be realized within the scope of theinvention. For example, any suitable latching mechanism can be used, ascan any suitable materials. Also, the connector can be adapted to anystandard or proprietary layout. Therefore, the present invention shouldbe construed as limited only by the appended claims.

1. An electrical connector for an electric vehicle, the electricalconnector comprising: a connector body; a plurality of connector pins inthe connector body; and a latch mounted in a latch area on the connectorbody for holding the electrical connector to the electric vehicle;wherein the connector body has a plurality of holes for allowing waterentering the latch area to exit the latch area.
 2. The electricalconnector of claim 1, further comprising a light adjacent to theplurality of connector pins.
 3. The electrical connector of claim 2,further comprising a second light on a portion of the connector bodyopposite to the connector pins.
 4. The electrical connector of claim 1,wherein the connector body is formed by overmolding.
 5. The electricalconnector of claim 1, wherein the connector body comprises: a pottingcompound; a premold formed over the potting compound; and an outerconnector body formed in a single piece over the premold.
 6. Theelectrical connector of claim 5, wherein the potting compound comprisesa two-part dielectric potting compound.
 7. The electrical connector ofclaim 6, wherein the premold comprises a material selected from thegroup consisting of polyamide-based materials, glass-filled polyethyleneterephthalate, acrylonitrile butadiene styrene, thermoplastic elastomer,thermoplastic vucanizate, and polypropylene.
 8. The electrical connectorof claim 7, wherein the outer connector body comprises a materialselected from the group consisting of EPT, EPDM and silicone or liquidsilicone injection.
 9. The electrical connector of claim 5, wherein thepremold is formed to provide at least one of cross-linking adhesion,mechanical bonding, and mechanical locking with the outer connectorbody.
 10. A method for making an electrical connector for an electricvehicle, the method comprising: (a) providing a charging cable and aconnector body having at least one connector pin; (b) providing anelectrical connection between the charging cable and the at least oneconnector pin; (c) applying a potting compound over the connector bodyand a portion of the charging cable adjacent to the connector body; (d)applying a premold over the potting compound, the connector body, andthe portion of the charging cable adjacent to the connector body; and(e) overmolding an outer connector body in a single piece over thepremold to form the connector.
 11. The method of claim 10, furthercomprising providing circuitry to control operation of the connector,and wherein step (c) comprises applying the potting compound over thecircuitry.
 12. The method of claim 10, wherein the potting compoundcomprises a two-part dielectric potting compound.
 13. The method ofclaim 12, wherein the premold comprises a material selected from thegroup consisting of polyamide-based materials, glass-filled polyethyleneterephthalate, acrylonitrile butadiene styrene, thermoplastic elastomer,thermoplastic vucanizate, and polypropylene.
 14. The method of claim 13,wherein the outer connector body comprises a material selected from thegroup consisting of EPT, EPDM and silicone or liquid silicone injection.15. The method of claim 10, wherein the premold is formed to provide atleast one of cross-linking adhesion, mechanical bonding, and mechanicallocking with the outer connector body.
 16. The method of claim 10,further comprising attaching a latch to the connector for latching theconnector onto the vehicle.
 17. The method of claim 16, wherein theouter connector body has a latch formed therein.
 18. The method of claim17, wherein the outer connector body has a plurality of holes forallowing water entering the latch area to exit the latch area.
 19. Themethod of claim 18, wherein step (e) comprises overmolding the outerconnector body to have the plurality of holes.